using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using FarmmapsApi;
using FarmmapsApi.Models;
using FarmmapsApi.Services;
using FarmmapsDataDownload.Models;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using static FarmmapsApiSamples.Constants;

namespace FarmmapsDataDownload
{
    public class DataDownloadApplication : IApplication
    {
        private const string DownloadFolder = "Downloads";
        private const string SettingsFile = "settings.json";

        private readonly ILogger<DataDownloadApplication> _logger;
        private readonly FarmmapsApiService _farmmapsApiService;
        private readonly DataDownloadService _dataDownloadService;
        private readonly GeneralService _generalService;

        private Settings _settings;

        public DataDownloadApplication(ILogger<DataDownloadApplication> logger, FarmmapsApiService farmmapsApiService,
            GeneralService generalService, DataDownloadService dataDownloadService)
        {
            _logger = logger;
            _farmmapsApiService = farmmapsApiService;
            _generalService = generalService;
            _dataDownloadService = dataDownloadService;
        }

        public async Task RunAsync()
        {
            var fieldsInputJson = File.ReadAllText("DataDownloadInput.json");
            List<DataDownloadInput> fieldsInputs = JsonConvert.DeserializeObject<List<DataDownloadInput>>(fieldsInputJson);

            if (!Directory.Exists(DownloadFolder))
                Directory.CreateDirectory(DownloadFolder);

            // !! this call is needed the first time an api is called with a fresh clientid and secret !!
            await _farmmapsApiService.GetCurrentUserCodeAsync();
            var roots = await _farmmapsApiService.GetCurrentUserRootsAsync();

            foreach (var input in fieldsInputs)
            {
                try
                {
                    await Process(roots, input);
                }
                catch (Exception ex)
                {
                    _logger.LogError(ex.Message);
                }
            }
        }

        private async Task Process(List<UserRoot> roots, DataDownloadInput input)
        {
            // !!specify if you are using an already created cropfield:
            bool useCreatedCropfield = input.UseCreatedCropfield;
            var cropYear = input.CropYear;
            var fieldName = input.fieldName;
            bool storeSatelliteStatistics = input.StoreSatelliteStatistics;
            string settingsfile = $"Settings_{fieldName}.json";

            LoadSettings(settingsfile);

            var uploadedRoot = roots.SingleOrDefault(r => r.Name == "Uploaded");
            if (uploadedRoot == null)
            {
                _logger.LogError("Could not find a needed root item");
                return;
            }

            var myDriveRoot = roots.SingleOrDefault(r => r.Name == "My drive");
            if (myDriveRoot == null)
            {
                _logger.LogError("Could not find a needed root item");
                return;
            }

            // Use already created cropfield or create new one
            Item cropfieldItem;
            if (useCreatedCropfield == false || string.IsNullOrEmpty(_settings.CropfieldItemCode))
            {
                _logger.LogInformation("Creating cropfield");
                cropfieldItem = await _generalService.CreateCropfieldItemAsync(myDriveRoot.Code,
                    $"DataCropfield {input.OutputFileName}", cropYear.Year, input.GeometryJson.ToString(Formatting.None));
                _settings.CropfieldItemCode = cropfieldItem.Code;
                SaveSettings(settingsfile);
            }
            else
            {
                _logger.LogInformation("Cropfield already exists, trying to get it");
                cropfieldItem = await _farmmapsApiService.GetItemAsync(_settings.CropfieldItemCode);
            }


            // Get shadow data

            if (input.GetShadowData)
            {
                _logger.LogInformation("Calculate shadow map for field");
                var shadowItem = await _generalService.RunShadowTask(cropfieldItem);
                if (shadowItem == null)
                {
                    _logger.LogError("Something went wrong while obtaining the shadow map");
                    return;
                }

                _logger.LogInformation("Downloading shadow map");
                await _farmmapsApiService.DownloadItemAsync(shadowItem.Code,
                    Path.Combine(DownloadFolder, $"{input.OutputFileName}_shadow.zip"));
            }




            // Get satellite data
            if (input.GetSatelliteData)
            {
                // check if satellite task not yet done, do here and save taskcode
                if (useCreatedCropfield == false || string.IsNullOrEmpty(_settings.SatelliteTaskCode))
                {
                    var satelliteTaskCode = await _generalService.RunSatelliteTask(cropfieldItem);
                    _settings.SatelliteTaskCode = satelliteTaskCode;
                    SaveSettings(settingsfile);
                }
                
                // Select a particular satellite item from satelliteTask
                Item satalliteItem = await _generalService.FindSatelliteItem(cropfieldItem, _settings.SatelliteTaskCode);
                int selectedLayer= 2;

                if (input.SatelliteBand == "ndvi") selectedLayer = 0;
                if (input.SatelliteBand == "wdvi") selectedLayer = 1;
                if (input.SatelliteBand == "natural") selectedLayer = 2;

                var satelliteBand = satalliteItem.Data["layers"][selectedLayer]["name"];

                //Store satellite data to csv 
                if (storeSatelliteStatistics == true && (selectedLayer == 0 || selectedLayer ==1))
                {
                    var satelliteStatistics = satalliteItem.Data["layers"][selectedLayer]["renderer"]["band"]["statistics"];
                    Console.WriteLine($"Satellite image date: {satalliteItem.DataDate}");

                    var SatelliteStatsFile = $"{DownloadFolder}/SatelliteDataStatistics_{fieldName}_{input.SatelliteBand}_{satalliteItem.DataDate.Value:yyyy-MM-dd}.csv";
                    using var w = new StreamWriter(SatelliteStatsFile);
                    {
                        foreach (var item in satelliteStatistics)
                        {
                            var line = string.Format("{0}", item);
                            w.WriteLine(line);
                            w.Flush();
                        }
                    }

                }

                var inputType = (satalliteItem.Data["layers"] as JArray)?[selectedLayer]["name"].ToString();
                if (string.IsNullOrEmpty(inputType))
                {
                    _logger.LogError("Could not get the input type name from the satellite item");
                    return;
                }

                // download the geotiff of needed inputtype
                var SatelliteImageDate = (DateTime)satalliteItem.DataDate;
                var SatelliteDate = SatelliteImageDate.ToString("yyyyMMdd");
                _logger.LogInformation("Downloading geotiff file");
                await _farmmapsApiService.DownloadItemAsync(satalliteItem.Code,
                    Path.Combine(DownloadFolder, $"satelliteGeotiff_{input.OutputFileName}_{inputType}_{SatelliteDate}.zip"));
            }


            // Get vanDerSat data
            if (input.GetVanDerSatData)
            {
                // check if satellite task not yet done, do here and save taskcode
                if (useCreatedCropfield == false || string.IsNullOrEmpty(_settings.VanDerSatTaskCode))
                {
                    var vanDerSatTaskCode = await _generalService.RunVanDerSatTask(cropfieldItem);
                    _settings.VanDerSatTaskCode = vanDerSatTaskCode;
                    SaveSettings(settingsfile);
                }

                // Select a particular satellite item from satelliteTask
                Item vanDerSatItem = await _generalService.FindVanDerSatItem(cropfieldItem, _settings.VanDerSatTaskCode, fieldName,  input.StoreVanDerSatStatistics);
                


            }


        }

        // Functions to save previously created cropfields
        private void LoadSettings(string file)
        {
            if (File.Exists(file))
            {
                var jsonText = File.ReadAllText(file);
                _settings = JsonConvert.DeserializeObject<Settings>(jsonText);
            }
            else
            {
                _settings = new Settings();
            }
        }

        private void SaveSettings(string file)
        {
            if (_settings == null)
                return;

            var json = JsonConvert.SerializeObject(_settings);
            File.WriteAllText(file, json);
        }
        private void SaveInfo(string file)
        {
            if (_settings == null)
                return;

            var json = JsonConvert.SerializeObject(_settings);
            File.WriteAllText(file, json);

        }

    }
}